1. In an obvious and provable manner
   - demonstrably, incontrovertibly, irrefutably

See also: provable

• optical maser
• optical opacity
• optical phenomenon
• optical prism
• optical pyrometer
• optical rotation
• Inverness
• inverse
• inverse cosecant
• inverse cosine
• inverse cotangent
• inverse function
• inverse secant
• inverse sine
• inverse tangent
• inversely
• inversion
• invert
• invert soap
• invert sugar
• invertase
• invertebrate
• invertebrate foot
• inverted
• inverted comma